Relationship between a Female Guppy’s Anal Fin and a Male’s Mating Behaviors

Sarah Ervin, Joseph Goodhue, John Hatheway, Nick Hazell, Jie Ren


Sexual selection and the various factors that apply to it are important topics that researchers have studied
for years. Sexual selection, a theory by Darwin, is a form of natural selection in which a male or female
is attracted to certain physical characteristics or behaviors when mating, causing a genetic change in the
species. In our experiment, we measured the mate choice of male guppies (Poecilia reticulata) on female
guppies with and without anal fins. To do this, we used two orange 3D guppy models, one without an
anal fin and one with an anal fin, and placed them in either side of the tank while measuring how many
mating behaviors were displayed to each model and how much time was spent on each side of the tank.
Each trial lasted five minutes. We hypothesized that the male guppy would be more attracted to the
female with the anal fin because the fin is used in reproduction. The results support our hypothesis
because, on average, the male guppy spent more time on the side of the tank with the female model with
the anal fin and displayed more mating behaviors toward this model as well. In comparison to other
studies about how anal fins affect mate selection, our experiment had completely opposite results. Our
study adds research to how the fins of female guppies influence male mate choice, which is beneficial
because the majority of sexual selection experiments involve the ornamentation of size of female models.

Full Text:



Endler, J.A. 1991. Variation in the appearance of guppy color patterns to guppies and their

predators under different visual conditions. Vision Research 31: 587-608.

Evans, J.P., A. Bisazza, and A. Pilastro. 2004. Female mating prefernces for colorful males in a

population of guppies subject to high predation. Journal of Fish Biology. 65:1154-1159.

Francis, E., M. Ogle, G. Penna, K. Perkins, and J. Wormington. 2015. I’m warming up to you:

Male guppies are attracted to warm colored females. Journal of Introductory Biology

Investigations. 2:5,1-5.

French, D.P. Investigating Biology: a Laboratory Resource Manual. Ed. Moria Harmon and

Aimee Elmquest. 2016 Edition. Southlake: Fountainhead Press, 2016. I4.1-I4.10.

Holmquest, T., B. Corckett-Beck, C. Ellington, M. Kane, S. Hileman. 2016. Determining Male

Sexual Selection In the Presence of Anal Fins Present On Model Fish. Journal of

Introductory Biology Investigations 4: 1-4.

Houde, A.E. 1997. Sex, color, and mate choice in guppies. Princeton, NJ: Princeton University


Kodric-Brown, A. 1993. Female choice of multiple male criteria in guppies—interacting effects

of dominance, coloration and courtship. Behavioral Ecology and Sociobiology 32: 415-420.

Kodric-Brown, A. 1989. Dietary carotenoids and male mating success in the guppy: an

environmental component to female choice. Journal of Behavioral Ecology and

Sociobiology. 25:393-401.

Majors, M., R. Kane, A. Ozgul, N. Koemel, and J. Agan. 2015. Color and size effects on male

guppy mate selection. Journal of Introductory Biology Investigations. 2:5,1-4.

Miller, L.K. and R. Brooks. 2007. The effects of genotype, age, and social environment on male

ornamentation, mating behavior, and attractiveness. Evolution. 59:2414-2425.

Turner, C.L. 1941. Gonopodial characteristics produced in the anal fins of females of gambusia

affinis by treatment of ethinyl testosterone. Marine Biological Laboratory. 80: 371-383.


  • There are currently no refbacks.